Bryan and Adam have a total of $189.
Bryan spends
13 of his money and
Adam spends
18 of his money.
They spend $33 altogether.
- How much does Bryan have at first?
- How much does Adam have in the end?
|
Bryan |
Adam |
Before |
3 u |
8 p |
Change |
- 1 u |
- 1 p |
After |
2 u |
7 p |
(a)
Amount that Bryan has at first = 3 u
Amount that Adam has at first = 8 p
Total amount that they have = 3 u + 8 p = 189 --- (1)
Total amount that they spend = 1 u + 1 p = 33 --- (2)
(2)
x 8 8 u + 8 p = 264 --- (3)
(3) - (1)
(8 u + 8 p) - (3 u + 8 p) = 264 - 189
8 u + 8 p - 3 u - 8 p = 264 - 189
8 u - 3 u + 8 p - 8 p = 75
8 u - 3 u = 75
5 u = 75
1 u = 75 ÷ 5 = 15
Substitute 1 u = 15 into (1).
3 u + 8 p = 189
3 x 15 + 8 p = 189
45 + 8 p = 189
8 p = 189 - 45 = 144
1 p = 144 ÷ 8 = 18
Amount that Bryan has at first
= 3 u
= 3 x 15
= $45
(b)
Amount that Adam has in the end
= 8 p - 1 p
= 7 p
= 7 x 18
= $126
Answer(s): (a) $45; (b) $126